Comparison between different direct search optimization algorithms in the calibration of a distributed hydrological model

where qm and qs are observed and simulated discharge flows at the gauges represented in Figure 2b, Vm and Vs are the observed and simulated cumulated volumes, FDCm and FDCs are the observed and simulated Flow Duration Curves and n is the number of time instants. The comparison was made on the period 1 January – 31 December 2005. Figure 3a. Comparison between observed and simulated discharge flows in Ambra basin (top panel). Cost function evaluations with all three algorithms (bottom panel, filling space phase is not represented for EGO).